Answer
$m^{-1/3} \left( 3m-4 \right)$
Work Step by Step
Factoring the given factor, $
m^{-1/3}
,$ then the given expression, $
3m^{2/3}-4m^{-1/3}
,$ is equivalent to
\begin{array}{l}\require{cancel}
m^{-1/3} \left( \dfrac{3m^{2/3}}{m^{-1/3}}-\dfrac{4m^{-1/3}}{m^{-1/3}} \right)
\\\\=
m^{-1/3} \left( 3m^{\frac{2}{3}-\left(-\frac{1}{3}\right)}-4m^{-\frac{1}{3}-\left(-\frac{1}{3} \right)} \right)
\\\\=
m^{-1/3} \left( 3m^{\frac{2}{3}+\frac{1}{3}}-4m^{-\frac{1}{3}+\frac{1}{3}} \right)
\\\\=
m^{-1/3} \left( 3m^{\frac{3}{3}}-4m^{0} \right)
\\\\=
m^{-1/3} \left( 3m^{1}-4(1) \right)
\\\\=
m^{-1/3} \left( 3m-4 \right)
.\end{array}
